Elements used for radioactive dating Live sex chat room for ipad
For potassium 40, the half-life is about 1.3 billion years.
In general, in one half-life, half of the parent will have decayed.
We can assume that the Precambrian rocks already existed when life began, and so the ages of the Precambrian rocks are not necessarily related to the question of how long life has existed on earth.
The Cambrian period is conventionally assumed to have begun about 550 million years ago.
We are told that of all the radiometric dates that are measured, only a few percent are anomalous.
Therefore, my main concern is with rocks of the Cambrian periods and later.At the start, let me clarify that my main concern is not the age of the earth, the moon, or the solar system, but rather the age of life, that is, how long has life existed on earth.Many dating methods seem to give about the same ages on meteorites.Perhaps the earth was made from older pre-existing matter, or perhaps decay rates were briefly faster for some reason. Geologic time is divided up into periods, beginning with the Precambrian, followed by the Cambrian and a number of others, leading up to the present.When one considers the power of God, one sees that any such conclusions are to some extent tentative. Some fossils are found in Precambrian rocks, but most of them are found in Cambrian and later periods.